Robotically guiding the trajectory of a second surgical device

ABSTRACT

Robotic systems and methods are provided for trajectory guidance during surgical procedures, for example, robotically monitoring and identifying a desired trajectory of surgical access devices and implants for the purpose of preventing unintended injury to surrounding tissues, such as nerves, blood vessels, cartilage, or bone. The robotic systems and methods provided herein allow medical professionals to practice with little to no exposure of the medical professional to radiation.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. application Ser.No. 16/258,529, filed Jan. 25, 2019, which claims priority to U.S.Provisional Application No. 62/622,088, filed Jan. 25, 2018, each ofwhich is hereby incorporated herein by reference in its entirety.

BACKGROUND Field of the Invention

The present disclosure relates generally to surgical systems andmethods, and more particularly to systems and methods for guiding thetrajectory of a surgical device during surgical procedures.

Description of Related Art

Medical procedures involving the vertebrae are normally complicatedbecause of the preciseness and accuracy required to avoid both neuraldamage and injury to major blood vessels. Precision depth guidedinstruments are required to perform percutaneous spinal surgery. Thesesurgeries sometimes require penetration of the hard cortical bone of thevertebra and traversal of the softer cancellous bone lying thereunder. Alarge force is normally required by the surgeon to penetrate thecortical bone. Once the cortical bone is penetrated, extreme care mustthen be taken to avoid rapidly penetrating through all of the cancellousbone. There is also the danger of rapidly passing through the cancellousbone and then through the cortical bone on the other side of thevertebra. This can result in injury or damage to the spinal cord and/orother organs or blood vessels located adjacent the spine. In someinstances, the force required to penetrate the cortical bone is greaterthan a surgeon can apply by hand. In these instances, a hammer or othersimilar instrument is required to force the instrument through thecortical bone. When a hammer or similar instrument is used, there is agreater danger of the instrument passing rapidly through the cancellousbone and out the other side of the vertebra.

In many instances during a minimally invasive spine surgery, for examplea TLIF procedure, a single incision is used for multiple steps,including but not limited to accessing and cleaning a disc space,inserting an implant into the disc space, and placing bone anchors (e.g.pedicle screws). This technique is useful but not without disadvantages,including but not limited to tissue disruption, and approach angle intodisc space being problematic for larger implants.

For at least the above reasons, one of skill will appreciate havingsystems and methods for monitoring and identifying a desired trajectoryof surgical access devices and implants for the purpose of preventingunintended injury to surrounding tissues, such as nerves, blood vessels,cartilage, or bone. The systems and methods provided herein, forexample, allow the surgeon to set the trajectory of a surgical accessdevice, with precision and accuracy, before ever cutting a subject'sskin. Moreover, due to the safety advantages of the use of Kambin'sTriangle in accessing tissue during a spinal surgery, one of skill willparticularly appreciate the surprisingly effective ability of thesystems and methods provided herein to set a trajectory for access toKambin's Triangle before ever cutting the skin of the subject at thisdesirable access point.

SUMMARY

Systems and methods for trajectory guidance during surgical proceduresare provided herein. For example, systems and methods are provided formonitoring and identifying a desired trajectory of surgical accessdevices and implants for the purpose of preventing unintended injury tosurrounding tissues, such as nerves, blood vessels, cartilage, or bone.

Methods of setting a trajectory angle for access by a second surgicaldevice into a subject by referencing a first surgical device areprovided, for example. In some embodiments, the methods can includeimplanting a portion of the reference surgical device in the subject toset a reference trajectory angle, which is a first direction ofangulation and a first angle of first access into a subject, wherein thereference trajectory angle is formed by the central axis of theimplanted portion of the reference surgical device; and, establishingthe trajectory angle for access by the second surgical device which is asecond direction of angulation and a second angle of second access intothe subject, using the central axis of the implanted portion of thefirst surgical device forming a reference point of origin, theestablishing including measuring the trajectory angle from the referencepoint of origin.

In some embodiments, the measuring includes obtaining a trajectoryguidance device operable for attaching to the reference surgical device.And, in some embodiments, the reference surgical device has an implantedportion, also referred to as an access portion, and a structural portionhaving a central axis, and the measuring includes obtaining a trajectoryguidance device adapted for attaching to the structural portion of thereference surgical device. In some embodiments, the trajectory guidancedevice can have a guidance portion with a first rotatable axisconcentric, or near concentric, with the central axis of the structuralportion of the reference surgical device when attached; and, an anglescale portion for determining the trajectory angle for access by thesecond surgical device.

One of skill will appreciate that the reference surgical device can beany point of reference used surgically to establish a point of originfor setting the trajectory of access for the second surgical device. Forexample, the reference surgical device is a pin, a needle, a rod, ascrew, or a combination thereof. In some embodiments, the referencesurgical device is a trephine. And, in some embodiments, the referencesurgical device is a Jamshidi needle. In some embodiments, the secondsurgical device is a dilator. And, in some embodiments, the secondsurgical device is a catheter.

One of skill will appreciate the value of the systems and methods inspinal surgeries. In some embodiments, the first surgical device can beimplanted into a vertebral pedicle at the reference trajectory angle,and the trajectory angle for access by the second surgical device secondsurgical device can be established for access into the Kambin's Triangleadjacent to the vertebral pedicle.

One of skill will also appreciate having the systems and methodsprovided herein in the form of a kit for ease of access and use. In someembodiments, a kit for performing a spinal surgery on a subject isprovided and includes a first surgical device having an access portionand a structural portion having a central axis; a second surgical devicehaving an access portion with a central axis; and, a trajectory guidancedevice adapted for operably connecting with the structural portion ofthe first surgical device and having an angle measurement component,such as the angle scale portion, to establish the trajectory of accessinto the subject by the access portion of the second surgical device. Insome embodiments, the first surgical device is a trephine, the secondsurgical device is a dilator, and the trajectory guidance device has aguidance portion with a first rotatable axis concentric, or nearconcentric, with the central axis of the structural portion of the firstsurgical device when attached; and, an angle scale portion fordetermining the trajectory angle of the access portion of the seconddevice for the access into the subject.

BRIEF DESCRIPTION OF THE DRAWINGS

Many advantages of the present disclosure will be apparent to thoseskilled in the art with a reading of this specification in conjunctionwith the attached drawings, wherein like reference numerals are appliedto like elements and wherein:

FIG. 1 is a side view of one example embodiment of a trajectory guidanceinstrument, illustrated with a Jamshidi needle and a partial view of aC-arm type x-ray device, according to some embodiments;

FIG. 2 is a top view of the trajectory guidance instrument of FIG. 1 ,according to some embodiments;

FIG. 3 is a perspective view of one example of an outrigger forming partof the trajectory guidance instrument of FIG. 1 , according to someembodiments;

FIG. 4 is a representative illustration of a portion of a human spine,illustrating in particular the location of Kambin's Triangle, accordingto some embodiments;

FIGS. 5A and 5B are radiographic images illustrating operation,according to some embodiments;

FIG. 6 is a side view of the trajectory guidance instrument of FIG. 1with the outrigger repositioned, according to one example, according tosome embodiments;

FIG. 7 is a side view of one example of a trajectory guidanceinstrument, according to some embodiments;

FIG. 8 is a radiographic image illustrating operation of the trajectoryguidance instrument of FIG. 7 , according to some embodiments;

FIG. 9 is a perspective view of the trajectory guidance instrument ofFIG. 7 in use with an example secondary approach instrument, accordingto some embodiments;

FIG. 10 is a radiographic image illustrating one step in the method,according to some embodiments; and,

FIG. 11 is a representative illustration of a portion of a human spine,illustrating the relative position of the trajectory guidance instrumentof FIG. 1 and a second approach instrument, according to someembodiments.

DETAILED DESCRIPTION

Systems and methods for trajectory guidance during surgical proceduresare provided herein. For example, systems and methods are provided formonitoring and identifying a desired trajectory of surgical accessdevices and implants for at least the purpose of preventing, or at leastavoiding or mitigating the risk of, an unintended injury to surroundingtissues, such as nerves, blood vessels, cartilage, or bone.

Methods of setting a trajectory angle for access by a second surgicaldevice into a subject by referencing a first surgical device areprovided, for example. In some embodiments, such methods can includeimplanting a portion of the reference surgical device in the subject toset a reference trajectory angle, which is a first direction ofangulation and a first angle of first access into a subject, wherein thereference angle is formed by the central axis of the implanted portionof the reference surgical device; and, establishing the trajectory anglefor access by the second surgical device using the central axis of theimplanted portion forming a reference point of origin, which is a seconddirection of angulation and a second angle of second access into thesubject, the establishing including measuring the trajectory angle fromthe reference point of origin.

In some embodiments, the measuring includes obtaining a trajectoryguidance device operable for attaching to the reference surgical device.And, in some embodiments, the reference surgical device has an implantedportion and a structural portion having a central axis, and themeasuring includes obtaining a trajectory guidance device adapted forattaching to the structural portion of the reference surgical device. Insome embodiments, the trajectory guidance device can have a guidanceportion with a first rotatable axis concentric, or near concentric, withthe central axis of the structural portion of the reference surgicaldevice when attached; and, an angle scale portion for determining thetrajectory angle for access by the second surgical device.

One of skill will appreciate that the reference surgical device can beany point of reference used surgically to establish a point of originfor setting the trajectory of access for the second surgical device. Forexample, the reference surgical device is a pin, a needle, a rod, ascrew, or a combination thereof. In some embodiments, the referencesurgical device is a trephine. And, in some embodiments, the referencesurgical device is a Jamshidi needle. In some embodiments, the secondsurgical device is a dilator. And, in some embodiments, the secondsurgical device is a catheter. The surgical instrument can be a cuttinginstrument or a dissecting instrument, a grasping instrument or aholding instrument, a hemostatic instrument, a retraction instrument, ora tissue-unifying instrument. Accordingly, one of skill will appreciatethat the “functional portion” of the surgical instrument will includethe portion of the surgical device that may be configured to do the“function”, which can be, for example, the cutting or dissecting, thegrasping or holding, the retracting, the tissue-unifying, the preventingof the flow of blood, or a combination thereof.

The term “animal” can be used interchangeably, in some embodiments, withthe terms “subject” and “patient”. Such terms can be used to refer to ananimal such as a mammal including, but not limited to, non-primates suchas, for example, a cow, pig, horse, cat, dog, rat and mouse; andprimates such as, for example, a monkey or a human. As such, the terms“subject” and “patient” can also be applied to non-human biologicapplications including, but not limited to, veterinary, companionanimals, commercial livestock, and the like. Moreover, “tissue” can beused to refer, for example, to epithelial tissue, connective tissue,muscle tissue and/or nerve tissue, in some embodiments. One of skillwill appreciate that epithelial tissues form the surface of the skin,and line many cavities of the body and covers the internal organs;connective tissue includes cartilage, bone, adipose, and blood, of whichcartilage and bone are of particular focus herein; muscle tissueincludes skeletal, smooth, and cardiac muscle; and the neural tissuesinclude neurons that process and transfer information throughout asubject's body. The tissue of interest in the surgical procedure caninclude, for example, intervertebral tissue and cortical portion of avertebral endplate, in some embodiments. The functional portion of thesurgical instrument can be configured, for example, to remove theintervertebral tissue.

One of skill will appreciate the value of the systems and methods inspinal surgeries. In some embodiments, the first surgical device can beimplanted into a vertebral pedicle at the reference trajectory angle,and the trajectory angle for access by the second surgical device secondsurgical device can be established for access into the Kambin's Triangleadjacent to the vertebral pedicle.

One of skill will also appreciate having the systems and methodsprovided herein in the form of a kit for ease of access and use. In someembodiments, a kit for performing a spinal surgery on a subject isprovided and includes a first surgical device having an access portionand a structural portion having a central axis; a second surgical devicehaving an access portion with a central axis; and, a trajectory guidancedevice adapted for operably connecting with the structural portion ofthe first surgical device and having an angle measurement component,such as the angle scale portion, to establish the trajectory of accessinto the subject by the access portion of the second surgical device. Insome embodiments, the first surgical device is a trephine, the secondsurgical device is a dilator, and the trajectory guidance device has aguidance portion with a first rotatable axis concentric, or nearconcentric, with the central axis of the structural portion of the firstsurgical device when attached; and, an angle scale portion fordetermining the trajectory angle of the access portion of the seconddevice for the access into the subject.

One of skill will appreciate that the systems and methods can includesteps set-forth in greater detail. In some embodiments, a method ofsetting a surgical trajectory for access by a second surgical deviceusing the fixed angle of a first surgical device in a subject caninclude, for example, obtaining a trajectory guidance device for a firstsurgical device and a second surgical device, the first surgical deviceand the second surgical device each having an access portion with a tipand a central axis concentric with the tip. The trajectory device canhave a guidance portion with a first rotatable axis concentric, or nearconcentric, with the central axis of the access portion of the firstsurgical device when in operable connection with the first surgicaldevice; and, a linear angle scale portion having a central axis at anangle, θ₁, from the first rotatable axis. The trajectory guidance devicecan be adapted for attaching to the first surgical device.

It should be appreciated that any surgical device can be used in themethods set-forth herein, and one of skill will appreciate that theselection of device depends on the function needed, which is determinedby the surgical procedure of interest. In some embodiments, the surgicaldevice is a pin, a needle, a rod, a screw, or a combination thereof.And, in some embodiments, the surgical device can be a dilator orcatheter. In some embodiments, the surgical device can be designed forcutting and dissecting, clamping and occluding, retracting and exposing,grasping and holding, or dilating and/or providing passage for anothersurgical instrument. Surgical instruments designed for single portsurgery can be used, for example. An example of a surgical instrumentthat can be used in a spinal procedure, such as a spinal fusionprocedure, is a trephine, such as a Jamshidi needle, and the trephinecan have a handle which can be adapted, for example, to accept thetrajectory guidance system, or serve as the trajectory guidance system,such as those taught herein.

In some embodiments, the methods include placing the guidance portion ofthe trajectory device in operable connection with the first surgicaldevice. The methods also can include obtaining a radiograph to helpestablish points of reference for the angulation of the surgicaldevices. For example, a radiograph of a target site within the subjectcan be obtained, the target site centered at or near the center of theradiograph, and the obtaining of the radiograph including directing theaxis of the central beam of a source of radiation for the radiograph ator near the center of the target site. It should be appreciated thatother imaging techniques can be used with the systems and methods taughtherein. An example of an alternative imaging system is ultrasound.Another examiner of an alternative imaging system is MRI (magneticresonance imaging). The trajectory guidance system can be marked for usewith the imaging system of choice. For example, an x-ray imaging systemcould be used with a trajectory guidance system that has radio-opaquemarkings to show angle measurements, and these markings can be placed inan at least substantially radiolucent support material for visualizationon the radiograph. Such markings can be used alone or “stacked”, suchthat markings intended to represent the same angle, on the top and onthe bottom of the guidance system, are superimposed when in alignment,or are separated when the markings are not aligned. Stacked markings canaid in determining if the established trajectory is potentiallyincorrect due to the positioning of the source of the x-ray, forexample.

In some embodiments, the methods include establishing a start positionof the first surgical device on the subject. Establishing the startposition can include, for example, placing the tip of the access portionof the first surgical device on the subject at a first point of entryfor a first access that is at or near the center of the radiograph; and,orienting the central axis of the access portion of the first surgicaldevice concentric or near concentric with the central beam of the sourceof radiation as a starting position for the first surgical device on theangle scale portion. The method can include establishing a firstdirection of angulation and a first angle of the first access into thesubject, the establishing including selecting the first direction ofangulation and the first angle for a first pivoting the central axis ofthe access portion relative to the central axis of the central beam. Themethod can also include aligning the central axis of the linear anglescale with the first direction of angulation for the first pivoting;and, while immobilizing the tip of the access portion of the firstsurgical device at the first point of entry, performing the firstpivoting of the central axis of the access portion of the first surgicaldevice in the first direction until the first angle for pivoting isreached on the linear angle scale. Fixing the first surgical device, thereference surgical device, at the first angle allows for use of thefirst surgical device as a reference point, in some embodiments. Thefixing of the first surgical device at the first angle can includeinitiating the first access into the subject at the first point of entryand penetrating the tip of the first surgical device to a first depthinto the subject that corresponds to a calibration of the first angle onthe linear angle scale.

It should be appreciated that the depth of the first access, or firstdepth, is the depth of the tip of the first surgical device andestablishes the point of angulation for the trajectory guidance device.Since the first angle is fixed, the method can include establishing thesecond direction of angulation and the second angle of the second accessinto the subject. It should be appreciated that the second direction ofangulation and the second angle originates from the tip of the firstsurgical device. As such, the establishing can include selecting thesecond direction of angulation and the second angle for the central axisof the access portion of the second surgical device relative to thecentral axis of the access portion of the first surgical device;aligning the central axis of the linear angle scale with the seconddirection of angulation; and, while immobilizing the tip of the accessportion of the second surgical device at the second point of entry,performing a second pivoting of the central axis of the access portionof the second surgical device in the second direction until the secondangle is reached on the linear angle scale.

As with the first surgical device, the second surgical device can befixed. In some embodiments, the fixing of the second surgical device atthe second angle is included, and the fixing includes initiating thesecond access into the subject at the second point of entry andpenetrating the tip of the second surgical device to a second depth intothe subject that corresponds to a calibration of the second angle on thelinear angle scale.

As noted above, the systems and methods provided herein are especiallyuseful in spinal procedures, for example, such as spinal fusionprocedures. In some embodiments, the target site is a vertebral pedicle,the first access is into the vertebral pedicle of the subject, and thesecond access is into the Kambin's Triangle adjacent to the vertebralpedicle. The first surgical device can be a pin, a needle, a rod, ascrew, or a combination thereof; a trephine, perhaps a Jamshidi needle;a dilator and/or perhaps a catheter. One of skill will appreciate thatthe surgical devices that can be used are numerous and not limited tothe above.

It should also be appreciated that a number of operable connections canbe designed for attaching the trajectory guidance device to the firstsurgical device, wherein the angle, θ₁, of the central axis of thelinear angle scale portion from the first rotatable axis of the guidanceportion of the linear angle scale ranges from about 45° to about 135°,and can be any amount or range therein in increments of 1°. And, in someembodiments, the angle scale is not linear but, rather curved like aprotractor. In some embodiments, the angle, θ₁, is about 50°, about 55°,about 60°, about 65°, about 70°, about 75°, about 80°, about 85°, about90°, about 95°, about 100°, about 105°, about 110°, about 115°, about120°, about 125°, about 130°, or any amount or range therein inincrements of 1°.

In should also be appreciated that the trajectory guidance device can beintegral with the first surgical device, such that the guidance deviceis part of the surgical device itself. However, it should also beappreciated that, whether integral or not, the trajectory guidancedevice can also be configured to rotate around the access portion of thefirst surgical device.

The embodiments and surgical uses of a trajectory guidance systemdescribed herein can be used to enhance the safety and efficiency ofsurgical procedures, as well as avoid and/or mitigate the risk of injuryduring a surgical procedure. In some embodiments, the systems andmethods provided herein may facilitate safe and reproducible pediclescrew placement by monitoring the axial trajectory of various surgicalinstruments used during pilot hole formation and/or screw insertion.

In some embodiments, intraoperative imaging performance may be improvedand radiation exposure minimized by monitoring the precise orientationof the imaging device. For example, a robotic system is provided,wherein the systems can include a robotic arm for manipulation of thefirst surgical device to a first desired angle, and establishing theangle and access of the second surgical device with little to noexposure of a medical professional to radiation. In some embodiments,the robotic system can include any control input device for controllingthe manipulation of the robotic arm. An example of such a control deviceis a joystick. An augmented system can include enhanced graphical userinterfaces including, for example, a head-mounted display, such as avirtual reality headset and/or simply a large screen that is magnifiedfor an enhanced graphical user interface. Such robotic systems can beequipped with a sensitive tactile feedback for enhanced control.

In particular, however, a method of using the systems and methods taughtherein can be controlled to prepare an intervertebral disc for a spinalfusion procedure. Such a method might include, for example, creating apoint of entry into an intervertebral disc, the intervertebral dischaving a nucleus pulposus surrounded by an annulus fibrosis; and,removing the intervertebral tissue from within the intervertebral space,the intervertebral space having a top vertebral plate and a bottomvertebral plate while preserving the annulus fibrosis.

In some embodiments, the method can be part of a spinal fusion procedurethat uses a scaffolding to support fusion of an intervertebral discspace, such that the method can further include inserting a scaffoldingthrough the point of entry into the intervertebral space; and, adding agrafting material to the intervertebral space for the fusion.

Such systems and methods can be computerized, and even robotic. One ofskill will understand that the methods and systems provided herein caninclude hardware and software, in some embodiments, the combination ofwhich can a “computer”, for example, having a processor and memory. Itshould also be understood that the technology provided herein alsoincludes “software”, which can include instructions for execution offunction by the processor, the software including, for example, a set ofmodules, engines, and instructions for executing the modules and/orengines by the processor. As such, in some embodiments, the system canfurther include an input module on a non-transitory computer readablestorage medium. The input module can, for example, receive input from an“operator”. The operator input can be used in identifying, for example,any surgical parameters of interest to a particular surgical procedure.

Robotics can increase safety and efficiency in techniques that requireprecision. However robotics may be used throughout the surgicalprocedure to increase safety and efficiency to several aspects. Forexample, one such aspect is determining an approach trajectory andestablishing an operative corridor to a surgical target site (e.g. anintervertebral disc space). In most cases, this aspect is performedmanually by a surgeon who never leaves the X-ray field even thoughnumerous (and in some instances, continuous) radiation exposure eventsmay happen during the procedure. This is especially hazardous forhigh-volume surgeons. In the current example, one or more surgicalneedles (e.g. Jamshidi needles) may be attached to the distal end(s) ofone or more robotic arms controlled by a computer system. The surgeoncan be out of the X-Ray field entirely, or at least substantially,without giving up the ability to control the positioning of the surgicalneedle while the medial-lateral approach angle is determined. Therobotically-positioned needle(s) may then be verified using additionaltargeting devices/techniques. Once established, the robotic arm may thencontinue to hold the surgical needle (and subsequent dilators,retractors, etc.) in place to establish and maintain an operativecorridor (e.g. minimally invasive, percutaneous, and/or open). The term“substantially” can be used to refer to an amount that is appreciable tothe skilled artisan. In some embodiments, a surgeon is out of an x-rayfield substantially when the radiation exposure is reduced by at leastabout 10%, about 20%, about 30%, about 40%, about 50%, about 60%, about70%, about 80%, about 90%, or any amount or range therein in amounts of1%.

As such, in some embodiments, the systems and methods can include asurgical device having a functional portion, and a robotic armconfigured for holding the surgical instrument and contacting thefunctional portion of the surgical instrument with an animal tissue.Likewise, the systems and methods can include a computer having aprocessor; and, a memory, wherein the memory can be configured toinclude, for example, a trajectory module on a non-transitory computerreadable storage medium. The trajectory module can be configured suchthat it is operable to instruct the processor to alter the trajectory ofthe access of a surgical device using the robotic arm.

It is important to note that even though the various method stepsdisclosed herein can be driven by robotics, they are not necessarilyoccurring unsupervised, but rather trained surgeons and/or technicianscan be nearby monitoring and controlling the data collection andoperation of the robotics instrument. One advantage of using robotics tocontrol the precision movements of the procedure is that the surgeonsand/or technicians can be out of the X-Ray field and still have theability to monitor and/or control the action of the robotics.

One of skill will appreciate that monitoring the orientation of surgicalaccess instruments can aid in both the insertion and positioning of theaccess instruments themselves, as well as aiding in the later insertionof instruments and/or implants through or with the surgical accessinstruments. In some embodiments, the trajectory guidance system may beused to measure multiple trajectory angles after placement of an initialsurgical instrument. It should be appreciated that the systems andmethods provided herein may be suitable for use in any number ofadditional surgical actions where the angular orientation or trajectoryor depth (linear distance traveled) of instrumentation and/or implantsis desired. In some embodiments, for example, the systems and methodsprovided herein may be useful in directing, among other things, theformation of tunnels for ligament or tendon repair and the placement offacet screws. Other uses may include orientation of drills, saws,cutters or other hand operated tools used in the performance of surgerywhere specific fiducial markers may be useful.

FIGS. 1-2 illustrate one example embodiment of the present disclosureand one manner in which it may be assembled, according to someembodiments. The example shown in FIGS. 1-2 is similar to that shown anddescribed in commonly-owned PCT Patent Application Serial numberPCT/US15/32235, filed 22 May 2015 and entitled “Trajectory GuidanceDevice and System for Surgical Instruments,” the entire contents ofwhich are incorporated by reference into this disclosure as if set forthfully herein. Note that identical reference numerals refer to likecomponents in the various figures. FIG. 1 is a schematic representationshowing an embodiment of a precision trajectory guidance instrument 100,illustrated herein as an outrigger 10, secured to a structural portionof a first surgical device, such as a Jamshidi needle 40. The outrigger10 comprises a radiolucent body portion 14 having radiopaque indicia 18forming a front sight 30 and a rear sight 32 which can be aligned underradiography for the purpose of preventing unintended injury tosurrounding tissues, nerves, blood vessels, cartilage or bone. Thevisibility of the indicia 18 under radiography ensures a precisetrajectory and/or monitoring of the trajectory of surgical instrumentsand/or implants in any number of surgical procedures, such as bonemarrow biopsies, placement of spinal implants, spinal surgery, includingensuring proper placement of pedicle screws during pedicle fixationprocedures, and ensuring proper trajectory during the establishment ofan operative corridor to a spinal target site. A trajectory indicium 19,e.g. rear sight 32, which is also radiopaque is provided for determiningan angular relationship and is aligned in a horizontal or vertical planebetween the front sights 30. The indicia 18 can also include at leastone reference trajectory sight 34, which indicates various degreegraduations between the front sights 30 that form an angle scale portionas shown in FIGS. 2 and 3 between front sights 30. In some embodiments,the indicia 18 may be embossed, printed, painted, embedded or otherwiseimprinted on a sticker, clip or outrigger. The radiopaque materialsutilized for the indicia may include one of several metals known to beradiopaque such as, but not limited to, lead, tantalum, tungsten, gold,stainless steel or the like. Alternatively, the indicia may be aradiopaque polymer; such polymers are available under the trade nameLATIGRAY from LATI Industries Thermoplasici S.p.A. of Italy, and may bedirectly adhered or molded into the outrigger.

By way of example only, while placing bone screws through a pedicle 42(which is a small generally tubular structure connecting posteriorelements of a vertebra 44 to the vertebral body), it is critical toensure the screw is contained within the pedicle and does not breach theouter pedicle wall. Since the pedicle 42 is surrounded by delicatenervous tissue, a breach can have serious consequences for the patient,ranging from mild pain to paralysis. One way to mitigate the risk of apedicle breach during screw placement (including preparation for screwplacement, such as pilot hole formation and tapping) is to determine theangular orientation of the pedicle, and thereafter advance the necessaryinstruments and screws along the determined trajectory. By orienting thesurgical access components along the pedicle trajectory, the surgicalinstruments and pedicle screws may be simply and efficiently advancedalong the same trajectory, and thus avoid a breach by “eyeballing”alignment with the access components.

Thus, in spinal surgery, before a pilot hole is formed with the Jamshidineedle 40, the desired angular trajectory must first be determined.Preoperative superior view utilizing AP fluoroscopy, MRI or CAT scanimaging device(s) 20 can be used to determine the trajectory once theJamshidi needle 40, in combination with the outrigger 10, has beenplaced at the anatomical site for which the surgery is to be conducted.C-arm fluoroscopes can be used extensively during many surgicalprocedures, for example. During spinal surgery for example, the C-armcan be used frequently to help locate specific structures of the spine,to direct the positioning of surgical instruments and/orinstrumentation, and to verify the proper alignment and height ofvertebra, among other uses. Imaging devices, such as the C-arm, aretypically provided with a scale (not shown) indicating the orientationof the radiography beam 24 with respect to the patient and thus, in thisexample, the Jamshidi needle 40 in combination with the outrigger 10. Inthis manner, the imaging device 20 can direct a radiography beam 24across the outrigger 10 at a known angle, causing the indicia 18 tobecome visible in the resulting image 20 (FIG. 2 ). As shown in FIG. 2 ,the indicia 18, e.g. front sight 30 can be viewed in combination withthe rear sight 32 to define the outer boundaries of the desired angle,which is visible between the front sights 30. Spacing between the frontsights 30 can be altered to provide any desired range of angleindication. It should also be noted that while only two front sights 30are illustrated, any number of reference trajectory sights 34 may beprovided to indicate angles or portions of angles without departing fromthe scope of the invention. In this manner, for surgical procedures suchas those to the spine wherein the coronal (medial) angle (shown asindicia 26 on FIG. 6 ) increases approximately 5 degrees per level, withrespect to centerline 28 from LI to the sacrum, a plurality of frontsights 30 or reference trajectory sights 34 may be provided, whereby thesurgeon can utilize a different front sight 30 or reference trajectorysight 34 for each level of the spine. In some embodiments, the frontsights 30, rear sight(s) 32 and reference trajectory sights 34 mayinclude different shapes including, but not limited to, numbers,letters, 2D and 3D geometric shapes and the like to indicate differentangles, sights or reference sights. The indicia 18 may or may not bevisible to the naked eye as the outrigger 10 is viewed. It should alsobe noted that while the present disclosure depicts a Jamshidi needle,the teachings of the present disclosure may be applied to other types ofsurgical tools without departing from the scope of the invention. Forexample, drills, saws, reamers, shapers and other hand-operated toolsused for surgical operations may benefit from the teachings of thepresent invention. In addition, the teachings of the present inventionmay be utilized for the implantation of various implants, catheters,scopes and the like without departing from the scope of the invention.It should be further noted that while the trajectory guidance device,such as the outrigger 10 of the present embodiment, is illustrated asbeing attached to the surgical tool, the teachings of the present deviceinclude that the trajectory guidance device may also be utilized as apermanently secured or integrally formed portion of a surgical toolwithout departing from the scope of the invention.

Referring to FIGS. 1 and 3 , one embodiment of an outrigger 10 isillustrated. In this embodiment, the radiolucent body portion 14 of theoutrigger is provided with a guidance portion, such as a tube portion50, for attachment to a structural portion of a surgical tool such as aJamshidi needle 40. The tube portion 50 includes an inner lumen 52 sizedto extend around the shaft 46. Thumb screws 54, friction or the like maybe utilized to hold the outrigger in place on the shaft 46 or any otherportion of a surgical tool that is generally round in shape. Thisconstruction also permits the outrigger 10 to be rotated as needed aboutthe surgical tool and additional radiography shots taken in differentplanes whereby compound angles and the like may be indicated by thedevice.

For example, one embodiment of the disclosure includes a method of usingthe rotatable outrigger 10 to safely and reproducibly determine theappropriate angle for accessing an intervertebral disc space throughKambin's Triangle, described herein with combined reference to FIGS.1-11 . Referring first to FIG. 4 , Kambin's Triangle refers to a righttriangular-shaped area adjacent two vertebral bodies defined by thesuperior border of the caudal vertebral body (e.g. base), thedura/traversing nerve root (e.g. height), and the exiting spinal nerveroot (e.g. hypotenuse). Accessing the disc space through this approachangle has several advantages, including minimizing damage to surroundingtissue and avoiding ligaments.

The first step in the example method is to deliver a surgical guidanceinstrument, for example the trajectory guidance instrument 100 describedabove (e.g. a Jamshidi needle 40 with attached outrigger 10), to atarget pedicle on a patient in the manner described above in relation toFIGS. 1-2 . For the purpose of illustration, the trajectory guidanceinstrument 100 is placed at an angle of 20° from center, however itshould be understood that the trajectory guidance instrument 100 may beplaced initially at any angle that is suitable and desirable to achievethe user's goals.

It should be appreciated that the trajectory guidance instrument can becalibrated to provide any desired angle. In some embodiments, thetrajectory guidance instrument can provide angles of about 1°, about 5°,about 10°, about 15°, about 20°, about 25°, about 30°, about 35°, about40°, about 45°, about 50°, about 55°, about 60°, about 65°, about 70°,about 75°, about 80°, about 85°, about 90°, or any amount or rangetherein in increments of 1°. In fact, the trajectory guidance instrumentcan include any desired gradations on the device for ease of referenceduring a surgical procedure as an angle scale portion as shown, forexample, at FIGS. 2 and 3 , and such gradations can include any of theangles listed herein, or even smaller gradations down to 0.1°.

Referring to FIGS. 5A and 5B, the next step is to verify that theapproach instrument (e.g. trajectory guidance instrument 100) is at theproper depth within the pedicle to correlate the desired depth foroptimal Kambin's trajectory. This is accomplished using the C-armfluoroscope described above, for example.

Referring to FIG. 6 , the next step is to reposition 25 the orientationof the outrigger 10, a full 180° relative to the first surgical deviceor reference device, such as the Jamshidi needle 40, the central axis 27of the implanted portion of the reference device forming a referencepoint of origin from which to measure a trajectory angle of the centralaxis of the implanted portion, or access portion, of a second surgicaldevice (not shown). By way of example, this may include a step ofrotating 25 the outrigger 10 about the Jamshidi needle 40 (e.g. forinstances in which the outrigger is of the type described with respectto FIG. 3 ), however, in other embodiments, the outrigger 10 may need tobe adjusted accordingly, to measure the trajectory angle of the centralaxis of the access portion of the second surgical device from thereference point of origin. This step of repositioning 25 the outrigger10 relative to the Jamshidi needle 40 (the position of which remainsunaltered) is necessary to achieve the approximately 45° approach anglerequired to enter the disc space through Kambin's Triangle. At thispoint, the angle of the Jamshidi needle 40 relative to the pedicle isknown by way of completion of the process of placing the Jamshidi needle40 described above. Since the angle needed to approach a disc spacethrough Kambin's Triangle is known to be approximately 45°, theadditional angle needed for the second approach instrument (to beadvanced through Kambin's Triangle, but not shown) may be calculated bysubtracting the placement angle of the Jamshidi needle 40 from therequired Kambin's approach angle. Thus in the instant example, 45°(required Kambin's approach angle) minus 20° (angle of the Jamshidineedle placement) equal 25° (required additional angle of secondapproach angle relative to the Jamshidi needle 40).

Referring to FIG. 7 , the outrigger 10 may include a secondary approachindicia 102 at the 25° mark to ensure proper alignment of the rotated 27outrigger 10 and to verify the correct angle for entry of the secondsurgical device through Kambin's Triangle. By way of example, thesecondary approach indicia 102 is depicted as a radiopaque circle,however any suitable radiopaque indicia may be used to verify the properangle has been achieved from the reference point of origin. As withplacement of the Jamshidi needle 40 described above, the imaging device20 can direct a radiography beam 24 across the outrigger 10 at a knownangle, causing the secondary approach indicia 102 to become visible inthe resulting image 103 (FIG. 8 ). As shown in FIG. 8 , the secondaryindicia 102 can be viewed under fluoroscopy to ensure proper positioningof the second surgical device relative to the disc space and Kambin'sTriangle. It should also be noted that while only one secondaryindicator 102 is illustrated (at the 25° mark), any number of secondaryindicia 102 may be provided to indicate angles or portions of angleswithout departing from the scope of the disclosure.

Referring to FIG. 9 , the next step is to secure the Kambin's approachangle of the second surgical device. By way of example, this may be doneby positioning a tube or cannula 104 such that the tube passes throughthe circle and the distal end of the tube 104 is touching the patient'sskin at the point of entry 106. Once the tube is properly aligned, anincision may be made in the patient's skin at the point of entry (e.g.where the tube touches the skin). The second approach instrument 108,the second surgical device, may then be advanced through the cannula 104(and incision) until it is about to reach the target disc. An x-rayimage may be used at this point (FIG. 10 ) to ensure proper trajectoryand to make any adjustments if necessary. Once the proper positioning ofthe second approach instrument 108 has been verified, the access portionof the second approach instrument may be pushed into the disc (FIG. 11).

At this point, the approach into the disc space through Kambin'sTriangle has been established, and the desired procedure may continue.For example, this may include expansion of the surgical corridor (e.g.via sequential dilation), removing disc material, insertingintervertebral implants, and the like.

We claim:
 1. A robotic method of setting a surgical trajectory foraccess by a second surgical device using a fixed angle of a firstsurgical device in a subject, the method comprising: obtaining a roboticsystem having a robotic arm configured for manipulation of a firstsurgical device to a first desired angle, and establishing an angle andaccess of a second surgical device with a trajectory guidance device; acontrol input device configured to receive input from an operator foridentifying surgical input parameters; a processor; a memory including atrajectory module on a non-transitory computer readable storage mediumand operable to instruct the processor to alter the trajectory of theaccess of the first surgical device or the second surgical device usingthe robotic arm and, a trajectory guidance device, the trajectoryguidance device for the first surgical device and the second surgicaldevice, the first surgical device and the second surgical device eachhaving an access portion with a tip and a central axis concentric withthe tip, the trajectory device having a guidance portion with a firstrotatable axis concentric, or near concentric, with the central axis ofthe access portion of the first surgical device when in operableconnection with the first surgical device; and, an angle scale portion;wherein, the trajectory guidance device is adapted for attaching to thefirst surgical device; placing the guidance portion of the trajectoryguidance device in operable connection with the first surgical device;obtaining a radiograph of a target site within the subject using asource of radiation having a central beam, the central beam having anaxis, and the radiograph having a center, the target site centered at ornear the center of the radiograph, the obtaining including directing theaxis of the central beam of a source of radiation for the radiograph ator near the center of the target site; manipulating the first surgicaldevice to the first desired angle with the robotic arm, the manipulatingincluding establishing a start position of the first surgical device onthe subject, the establishing including placing the tip of the accessportion of the first surgical device on the subject at a first point ofentry for a first access that is at or near the center of theradiograph; and, orienting the central axis of the access portion of thefirst surgical device concentric or near concentric with the centralbeam of the source of radiation as a starting position for the firstsurgical device on the angle scale portion; establishing a firstdirection of angulation and a first angle of the first access into thesubject, the establishing including selecting the first direction ofangulation and the first angle for a first pivoting the central axis ofthe access portion relative to the central axis of the central beam;aligning the angle scale with the first direction of angulation for thefirst pivoting; and, while immobilizing the tip of the access portion ofthe first surgical device at the first point of entry, performing thefirst pivoting of the central axis of the access portion of the firstsurgical device in the first direction of angulation until the firstangle for the first pivoting is reached on the angle scale; fixing thefirst surgical device at the first angle, the fixing includinginitiating the first access into the subject at the first point of entryand penetrating the tip of the first surgical device to a first depthinto the subject that corresponds to a calibration of the first angle onthe angle scale; and, establishing the angle and access of the secondsurgical device with the robotic arm, the establishing includingestablishing a second direction of angulation and a second angle of asecond access into the subject, the second direction of angulation andthe second angle originating from tip of the first surgical device, andthe establishing including selecting the second direction of angulationand the second angle for a second pivoting of the central axis of theaccess portion of the second surgical device relative to the centralaxis of the access portion of the first surgical device; aligning theangle scale with the second direction of angulation; and, whileimmobilizing the tip of the access portion of the second surgical deviceat a second point of entry, performing the second pivoting of thecentral axis of the access portion of the second surgical device in thesecond direction until the second angle is reached on the angle scale;and, fixing the second surgical device at the second angle, the fixingincluding initiating the second access into the subject at the secondpoint of entry and penetrating the tip of the second surgical device toa second depth into the subject that corresponds to a calibration of thesecond angle on the angle scale; wherein, the robotic system uses thetrajectory module to alter the trajectory of the access of the firstsurgical device and the second surgical device using the robotic arm. 2.The robotic method of claim 1, wherein the target site is a vertebralpedicle, the first access of the first surgical device is into thevertebral pedicle of the subject, and the second access of the secondsurgical device is into a Kambin's Triangle adjacent to the vertebralpedicle.
 3. The robotic method of claim 1, wherein the first surgicaldevice is a pin, a needle, a rod, a screw, or a combination thereof. 4.The robotic method of claim 1, wherein the first surgical device is atrephine.
 5. The robotic method of claim 1, wherein the first surgicaldevice is a trephine, and the second surgical device is a cuttinginstrument.
 6. The robotic method of claim 1, wherein the secondsurgical device is a dilator.
 7. The robotic method of claim 1, whereinthe second surgical device is a catheter.
 8. The robotic method of claim1, wherein the trajectory guidance device includes a secondary approachindicia for placement of the second surgical device.
 9. The roboticmethod of claim 1, wherein the trajectory guidance device rotates aroundthe access portion of the first surgical device for fixing the secondsurgical device at the second angle.
 10. A robotic method of setting atrajectory angle for access by a second surgical device into a subjectby referencing a first surgical device as a reference surgical device,the method comprising: obtaining a robotic system having a robotic armconfigured for manipulation of a reference surgical device to areference trajectory angle, and establishing an angle and access of asecond surgical device with a trajectory guidance device; a controlinput device configured to receive input from an operator foridentifying surgical input parameters; a processor; a memory including atrajectory module on a non-transitory computer readable storage mediumand operable to instruct the processor to alter the trajectory of theaccess of the reference surgical device or the second surgical deviceusing the robotic arm; and, an angle scale measurement component havingan angle scale portion; manipulating the reference surgical device tothe reference trajectory angle with the robotic arm, the manipulatingincluding implanting a portion of the reference surgical device in thesubject to set the reference trajectory angle, wherein the referencetrajectory angle is formed by the central axis of the implanted portionof the reference surgical device; and, establishing the angle and accessof the second surgical device with the robotic arm, the establishingincluding establishing the trajectory angle for access by the secondsurgical device using the central axis of the implanted portion of thereference surgical device as a reference point of origin, the secondsurgical device having an access portion with a tip and a central axis,the trajectory angle having a second direction of angulation and asecond angle of the central axis of the second surgical device, thetrajectory angle originating from the tip of the first surgical device,the establishing including immobilizing the tip of the access portion ofthe second surgical device at a second point of entry into the subject,performing a second pivoting of the central axis of the access portionof the second surgical device in the second direction of angulationuntil the second angle is reached; and, measuring the trajectory angleof the central axis of access portion of the second surgical device fromthe reference point of origin with an angle scale portion on an anglemeasurement component; wherein, the robotic system uses the trajectorymodule to alter the trajectory of the access of the reference surgicaldevice and the second surgical device using the robotic arm.
 11. Therobotic method of claim 10, wherein the measuring includes obtaining atrajectory guidance device for the robotic system, the trajectoryguidance device operable for attaching to the reference surgical device.12. The robotic method of claim 10, wherein the reference surgicaldevice has an implanted portion and a structural portion having acentral axis, and the measuring includes obtaining a trajectory guidancedevice for the robotic system, the trajectory guidance device adaptedfor attaching to the structural portion of the reference surgical deviceand having a guidance portion with a first rotatable axis concentric, ornear concentric, with the central axis of the structural portion of thereference surgical device when attached; and, an angle scale portion fordetermining the trajectory angle for access by the second surgicaldevice.
 13. The robotic method of claim 10, wherein the referencesurgical device is a pin, a needle, a rod, a screw, or a combinationthereof.
 14. The robotic method of claim 10, wherein the referencesurgical device is a trephine.
 15. The robotic method of claim 10,wherein the reference surgical device is a trephine, and the secondsurgical device is a cutting instrument.
 16. The robotic method of claim10, wherein the second surgical device is a dilator.
 17. The roboticmethod of claim 10, wherein the second surgical device is a catheter.18. The robotic method of claim 10, wherein the reference surgicaldevice is implanted into a vertebral pedicle at the reference trajectoryangle, and the trajectory angle for access by the second surgical deviceis established for access into the Kambin's Triangle adjacent to thevertebral pedicle.
 19. A robotic system for performing a spinal surgeryon a subject, the robotic system comprising: a first surgical devicehaving (i) an access portion and (ii) a structural portion having acentral axis; a second surgical device having an access portion with acentral axis; and, a robotic apparatus having a robotic arm configuredfor manipulation of a reference surgical device to a referencetrajectory angle, and establishing an angle and access of a secondsurgical device with a trajectory guidance device; a control inputdevice configured to receive input from an operator for identifyingsurgical input parameters; a processor; a memory including a trajectorymodule on a non-transitory computer readable storage medium and operableto instruct the processor to alter the trajectory of the access of thereference surgical device or the second surgical device using therobotic arm; and, a trajectory guidance device adapted for operablyconnecting with, and rotating about, the structural portion of the firstsurgical device, and having an angle measurement component with an anglescale portion to establish the trajectory of access into the subject bythe access portion of the second surgical device, wherein the anglemeasurement component comprises a rotatable portion and the angle scaleportion comprises a body comprising a front sight and a rear sightpositioned more distally than the front sight relative to a longitudinalaxis of the rotatable portion.
 20. The robotic system of claim 19,wherein the first surgical device is a trephine, the second surgicaldevice is a dilator, and the trajectory guidance device has a guidanceportion with a first rotatable axis concentric, or near concentric, withthe central axis of the structural portion of the first surgical devicewhen attached; and, an angle scale portion for determining thetrajectory angle of the access portion of the second device for theaccess into the subject.
 21. The robotic system of claim 19, wherein therotatable portion comprises a tube portion.
 22. The robotic system ofclaim 19, wherein the body is radiolucent and the sights are radiopaque.